Raising PullError when there's an error cloning or pulling

arca/_arca.py

@@ -7,9 +7,9 @@
 
 import re
 from dogpile.cache import make_region, CacheRegion
-from git import Repo, InvalidGitRepositoryError
+from git import Repo, InvalidGitRepositoryError, GitCommandError
 
-from .exceptions import ArcaMisconfigured, FileOutOfRangeError
+from .exceptions import ArcaMisconfigured, FileOutOfRangeError, PullError
 from .backend import BaseBackend
 from .result import Result
 from .task import Task
@@ -153,7 +153,10 @@ def _pull(self, *, repo_path: Path=None, git_repo: Repo=None, repo: str=None, br
             In a separate method so pulls can be counted in testing.
         """
         if git_repo is not None:
-            git_repo.remote().pull()
+            try:
+                git_repo.remote().pull()
+            except GitCommandError:
+                raise PullError("There was an error pulling the target repository.")
             return git_repo
         else:
             kwargs = {}
@@ -168,7 +171,10 @@ def _pull(self, *, repo_path: Path=None, git_repo: Repo=None, repo: str=None, br
                 kwargs["reference-if-able"] = str(reference.absolute())
                 kwargs["dissociate"] = True
 
-            return Repo.clone_from(repo, str(repo_path), branch=branch, **kwargs)
+            try:
+                return Repo.clone_from(repo, str(repo_path), branch=branch, **kwargs)
+            except GitCommandError:
+                raise PullError("There was an error cloning the target repository.")
 
     def current_git_hash(self, repo: str, branch: str, git_repo: Repo, short: bool=False) -> str:
         current_hash = self._current_hash[self.repo_id(repo)].get(branch)

arca/exceptions.py

@@ -12,6 +12,10 @@ class TaskMisconfigured(ValueError, ArcaException):
     pass
 
 
+class PullError(ArcaException):
+    pass
+
+
 class BuildError(ArcaException):
 
     def __init__(self, *args, extra_info=None, **kwargs):

tests/test_arca_class.py

@@ -9,7 +9,7 @@
 from git import Repo
 
 from arca import Arca, VenvBackend, CurrentEnvironmentBackend
-from arca.exceptions import ArcaMisconfigured, FileOutOfRangeError
+from arca.exceptions import ArcaMisconfigured, FileOutOfRangeError, PullError
 from common import BASE_DIR
 
 
@@ -365,3 +365,29 @@ def test_is_dirty():
     fl.unlink()
 
     assert not arca.is_dirty()
+
+
+def test_pull_error():
+    arca = Arca(base_dir=BASE_DIR)
+
+    git_dir = Path("/tmp/arca/") / str(uuid4())
+    git_url = f"file://{git_dir}"
+
+    with pytest.raises(PullError):
+        arca.get_files(git_url, "master")
+
+    filepath = git_dir / "test_file.txt"
+    repo = Repo.init(git_dir)
+    filepath.write_text(str(uuid4()))
+    repo.index.add([str(filepath)])
+    repo.index.commit("Initial")
+
+    arca.get_files(git_url, "master")
+
+    with pytest.raises(PullError):
+        arca.get_files(git_url, "some_branch")
+
+    shutil.rmtree(str(git_dir))
+
+    with pytest.raises(PullError):
+        arca.get_files(git_url, "master")